I've recently added an "odd" item to my kit that I'm finding extremely useful - Electrical Lacing cord - aka "12 cord". OK - it's string, and we all know we should have that, but this stuff is NICE. It's a nice, anout 1/16th round polyester string (nylon and cotton also available, as are other diameters and FLAT) - but besides that, it's waxed. It keeps it on the roll, makes it hold knots well. Downside? Not cheap unless you can find it surplus - usually available it "natural" (aka white) and UV resistant black. BTW this is the stuff that was used pre "wire ties" and is still used today in a lot of places